Adjustable bus bar for power distribution equipment

ABSTRACT

A busbar assembly for interconnecting electrical equipment units is disclosed. The busbar assembly includes one or more conductors have a conductive rod. Each end of the conductive rod has an end forming a ball member. The busbar assembly also includes two or more connectors having a clamp mechanism to receive the ball member of the conductive rod. A fastener threadably couples with a conductor on an electrical equipment unit to rigidly secure the busbar assembly to the electrical equipment units.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/977,992 filed on Apr. 10, 2014, the entire disclosure of which isincorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates generally to electrical powerdistribution equipment, and more particularly relates to an adjustablebusbar assembly for interconnecting electrical equipment such asswitchgear in the power distribution system.

BACKGROUND

This section provides background information related to the presentdisclosure that is not necessarily prior art.

A busbar assembly is used for interconnection of multiple electricalequipment units within a power distribution system. The busbar assemblymust be configured to attach and electrically couple with an electricalequipment unit, such as a switchgear unit. For example, a busbarassembly is used to interconnect multiple pole units within a switchgearunit in the power distribution system. It is important to provide arigid connection between the electrical equipment units for adequateelectrical coupling therebetween, and to avoid dielectric breakdown inthe interconnect areas.

Relative positional variation between the electrical equipment units maycreate difficulties when attempting to provide a rigid connectionbetween the electrical equipment units. For example, the connectionpoints between two switchgear units may not be properly aligned suchthat the busbar assembly must accommodate a misalignment. Inconventional busbar assemblies, a flexible cable is used betweenconnectors coupled to the switchgear units. While this has been shown toprovide effective coupling between the electrical equipment, it does notprovide a rigid connection therebetween.

Improved electrical coupling may be achieved with the use of aconductive rod between the contact points that provides for a rigidconnection. However, because the conductive rod cannot provideaccommodate misalignment between the electrical equipment units, thebusbar assembly should provide additional structure that provides thisfunctionality.

Accordingly, it is desirable to provide a busbar assembly that includesa conductive rod and connectors which account for positionalmisalignment between the electrical equipment, while providing a rigidelectrical coupling with the busbar assembly. In addition, it isdesirable to provide a busbar assembly that may be readily configuredfor different power distribution systems and various interconnectionstherebetween. Furthermore, other desirable features and characteristicsof the present invention will become apparent from the subsequentdetailed description of the invention and the appended claims, taken inconjunction with the accompanying drawings and this background of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are for illustrative purposes only ofselected embodiments and not all possible implementations, and are notintended to limit the scope of the present disclosure.

FIG. 1. is a perspective view illustrating three switchgear unitinterconnected by a busbar assembly;

FIG. 2 is a top view of the system shown in FIG. 1 and showingadditional switchgear units in broken lines;

FIG. 3 is a partial cross-section view taken through 3-3 shown in FIG.2;

FIG. 4 is a partial cross-section view taken through 4-4 in FIG. 2;

FIG. 5 is an expanded view of the adjustable busbar shown in FIG. 1; and

FIG. 6 is a cross-section of the busbar shown in FIG. 5 in assembledform.

Corresponding reference numerals indicate corresponding parts throughoutthe several views of the drawings.

DETAILED DESCRIPTION

A busbar assembly and a power distribution system are provided forinterconnecting at least two electrical equipment units such asswitchgear units. The busbar assembly includes a conductor having arigid conductive rod surrounded by an insulator sleeve. The conductiverod has first and second ends extending from the insulator sleeve and aball member formed on each end thereof. A first connector includes afirst insulator body having an interface configured to attach to a firstelectrical equipment unit. A first clamp mechanism is disposed in thefirst insulator body and configured to electrically couple with thefirst electrical equipment unit. The first end of the conductor isreceived in a first passage formed in the first insulator body such thatthe first ball member engages and electrically couples with the firstclamp mechanism. A second connector includes a second insulator bodyhaving an interface configured to attach to a second electricalequipment unit. A second clamp mechanism is disposed in the secondinsulator body and configured to electrically couple with the secondelectrical equipment unit. The second end of the conductor is receivedwithin a second passage formed in the second insulator body such thesecond ball member engages and electrically couples with the secondclamp mechanism.

The busbar assembly may be readily configured to interconnect more thantwo electrical equipment units. In this configuration, the busbarassembly also includes a second conductor having a second conductive rodsurrounded by a second insulator sleeve. The second conductive rod hasthird and fourth ends extending from the second insulator sleeve and aball member formed on each end thereof. A third connector includes athird insulator body having an interface configured to attach to a thirdelectrical equipment unit. A third clamp mechanism is disposed in thethird insulator body and configured to electrically couple with thethird electrical equipment unit. The third end of the conductor isreceived in a third passage formed in the third insulator body such thatthe third ball member engages and electrically couples with the thirdclamp mechanism. The fourth end of the second conductor is receivedwithin a fourth passage formed in the second insulator body such thefourth ball member engages and electrically couples with the secondclamp mechanism and the first conductive rod.

Example embodiments will now be described more fully with reference tothe accompanying drawings. There is no intention to be limited by anyprinciple presented in the preceding background or the followingdetailed description,

With reference now to FIGS. 1 and 2, a portion of a power distributionsystem is illustrated which includes a switchgear unit 10 having a setof pole units 12, 14, 16 interconnected by a busbar assembly 18. FIG. 1illustrates a first set of pole units 12, 14, 16 for one phase of athree-phase power distribution system interconnected by the busbarassembly 18. FIG. 2 schematically illustrates a switchgear unit 10having a second set of pole units 12′, 14′ 16′ (in broken lines)interconnected by a second busbar assembly 18′ and a third set of poleunits 12″, 14″, 16″ (in broken lines) interconnected by a third busbarassembly 18″. One skilled in the art will appreciate that second busbarassembly 18′ and third busbar assembly 18″ are substantially similar tofirst busbar assembly 18. Accordingly, further discussion concerning thestructure and functions of the component of the busbar assemblies willrefer to first busbar assembly 18.

With reference now to FIGS. 3-6, the busbar assembly 18 includes amolded bus or first conductor assembly (or simply “first conductor”) 20having a conductive rod 22 surrounded by an insulator sleeve 24. As bestseen in FIGS. 4 and 5, the conductive rod 22 includes a body portion 26,a first end 28 and a second end 30. Each of the first and second ends28, 30 extends from the insulator sleeve 24 and has a neck portion 28.1,30.1 and a head portion 28.2, 30.2, each defining a ball member. Aspresently preferred, the head portions 28.2, 30.2 form a spherical endportion having a contact surface.

With continued reference now to FIGS. 3-6, the busbar assembly 18includes a first connector 32 configured to attach to pole unit 112. Thefirst connector 32 includes an insulator body 34 having an interface 36(e.g., a tapered interior surface) configured to attach to the connector38 of pole unit 12. A clamp mechanism 40 in the form of an end clamppair is disposed in insulator body 34 and includes a first damp element42, a second clamp element 44 and a fastener 46. The fastener 46includes a head portion 48 having a first threaded portion 48.1 and asecond threaded portion 48.2 receiving a nut 49, and a shank 50extending from the threaded head portion 48 that passes through thefirst and second clamp elements 42, 44. A threaded body portion 52formed at the end of shank 50 is configured to engage a tapped hole 54in the conductor of pole unit 12. The fastener 46 functions to securethe first and second clamp elements 42, 44 around the first end 28 ofthe conductor 20. The fastener 46 may further include a biasing element122 such as a Belleville washer interposed between the nut 49 and thefirst clamp element 42 to tension the threaded coupling into tapped hole54. Connector 32 has a semi-conductive boot 128 surrounding the clampmechanism 40 and the first end 28 of the conductive rod 22. Connector 32further includes a plug assembly 142 threaded into recess 148. The plugassembly 142 includes an insulator body 154 threadably received inrecess 148 and an aluminum insert 160 that threads onto threaded portion48.1 of fastener 46.

A second connector 58 includes an insulator body 60 having an interface62 (e.g., a tapered interior surface) configured to attach to theconnector 64 of pole unit 14. A clamp mechanism 66 in the form of acenter clamp pair is disposed in insulator body 60 and includes a firstclamp element 68, a second clamp element 70 and a fastener 72. Thefastener 72 includes a head portion 74 having a first threaded portion74.1 and a second threaded portion 74.2 receiving a nut 75, and a shank76 extending from the threaded head portion 74 that passes through thefirst and second clamp elements 68, 70. A threaded body portion 78 isformed at the end of the shank 76 and configured to engage a tapped hole80 in the conductor of pole unit 14. The clamp mechanism 66 functions tosecure the first and second clamp elements 68, 70 around the second end30 of the conductor 20. The clamp mechanism 66 also functions to securethe first and second clamp elements 68, 70 around second end 94 of theconductor 84 as further described below. The fastener 72 may furtherinclude a biasing element 124 such as a Belleville washer interposedbetween the nut 75 and the first clamp element 68 to tension thethreaded coupling into tapped hole 80. Connector 58 has asemi-conductive boot 129 surrounding the clamp mechanism 66 and thesecond ends 30, 94 of the conductive rods 22, 86. Connector 58 furtherincludes a plug assembly 144 threaded into recess 150. The plug assembly144 includes an insulator body 156 threadably received in recess 150 andan aluminum insert 162 that threads onto first threaded portion 74.1 offastener 72.

In power distribution systems having more than two electrical equipmentunits interconnected, the busbar assembly 18 further includes a secondmolded bus or conductor assembly (or simply “second conductor”) 84 thatis similar to the first conductor 20. The second conductor 84 includes aconductive rod 86 surrounded by an insulator sleeve 88. The conductiverod 86 includes a body portion 90, a first end 92 and a second end 94.Each of the first and second ends 92, 94 extends from the insulatorsleeve 88 and has a neck portion 92.1, 94.1 and a head portion 92.2 to94.2 defining a ball member. As presently preferred, the head portion92.2, 94.2 forms a spherical end portion having a contact surface.

A third connector 96 is configured to attach to pole unit 16. The thirdconnector 96 includes an insulator body 98 having an interface 100(e.g., a tapered interior surface) configured to attach to the connector102 of pole unit 16. A clamp mechanism 104 in the form of an end clamppair is disposed in insulator body 98 and includes a first clamp element106, a second clamp element 108 and a fastener 110. The fastener 110includes a head portion 112 having a first threaded portion 112.1 and asecond threaded portion 112.2 receiving a nut 113, and a shank 114extending from the fastener head 112 that passes through the first andsecond clamp elements 106, 108. A threaded body portion 116 formed atthe end of shank 114 is configured to engage a tapped hole 118 in theconductor of pole unit 16. The clamp mechanism 104 functions to securethe first and second clamp elements 106, 108 around the first end 92 ofthe second conductor 84. The fastener 110 may further include a biasingelement 126 such as a Belleville washer interposed between the nut 113and the first clamp element 106 to tension the threaded coupling intothe tapped hole 118. Connector 96 has a semi-conductive boot 130surrounding the clamp mechanism 104 and the first end 92 of theconductive rod 86. Connector 96 further includes a plug assembly 146threaded into recess 152. The plug assembly 152 includes an insulatorbody 158 threadably received in recess 152 and an aluminum insert 164that threads onto the first threaded portion 112.1 of fastener 110.

The busbar assembly 18 illustrated in the figures provides a three-wayinterconnect for pole units of a single phase and includes conductors20, 84, and connectors 32, 58, 96. The first and third connectors 32, 96are end connectors that function to terminate the busbar assembly 18.The second connector 58 is an intermediate connector that functions toextend the busbar assembly 18 from the first conductor 20 to the secondconductor 84. One skilled in the art will appreciate that the connectorsand conductors described herein may be assembled into a busbar assemblythat provides a two-way interconnect for two pole units of a singlephase by eliminating the intermediate connector, or a busbar assemblythat provides for an interconnect for more than three pole units of asingle phase by adding additional intermediate connectors andconductors.

As presently preferred, the conductive rods 22, 86 are rigid aluminumrods, and insulator sleeves 24, 88 are made of a dielectric materialthat electrically insulates the conductive rods 22, 86. Likewise, thefirst clamp elements 42, 68, 106 and the second clamp elements 44, 70,108 are made of metal and may have an aluminum or copper plating toimprove electrical contact with the conductive rods 22, 86. Theinterfaces 36, 62, 100 shown in the figures are illustrated as taperedinterior surfaces, but one skilled in the art will appreciate that theinsulator body 34, 60, 98 may include any suitable interface forattaching the busbar assembly 18 to connectors 38, 64, 102 of electricalequipment units such as pole units 12, 14, 16 respectively.

As presently preferred, conductors 20, 84 have a conductive covering132, 134 on insulator sleeves 24, 88 and connectors 32, 58, 96 have aconductive covering 136, 138, 140 on insulator body 34, 60, 98.Conductive coverings 132-140 are conductively coupled when the busbarassembly 18 is assembled together. A grounding wire (not shown) mayextend between the conductive coverings 132-140 for grounding the busbarassembly 18.

To install the busbar assembly 18, the threaded body 52, 78, 116 offastener 46 72, 110 is threaded into tapped hole 54, 80, 118,respectively. The clamp mechanism 40, 66, 104 are then positioned inconnectors 32, 58, 96, respectively. Conductor 20, 84 are inserted intoconnectors 32, 96 so that first ends 28, 92 are located into clampmechanism 40, 104. Conductors 20, 84 are inserted into connector 58 sothat second ends 30, 94 are located into clamp mechanism 66. Soassembly, this adjustable busbar assembly may be located on pole unit12, 14, 16.

In particular, busbar connectors 32, 58 96 are positioned over pole unitconnectors 38, 64, 102, respectively. Shank 50, 76, 114 extends throughclamp mechanism 40, 66, 104, respectively to reveal threaded headportion 48, 74, 112 in recess 148, 150, 152. The adjustable busbaraccommodates misalignment between the pole units 12, 14, 16 by allowingthe ball members to move within the clamping mechanism. Once theconnector 32, 58, 96 are positively located onto the pole units, biasingelement 122, 124, 126 and nut 49, 75, 113 are secured onto the threadedhead portion 48, 74, 112 of fasteners 46, 72, 110 to clamp the clampmechanism 40, 66, 104 over first ends 28, 92 and second ends 30, 94,respectively. As presently preferred, nut 49, 75, 113 is tightened to atorque rating of about 50 to 60 ft.-lbs. Lastly, the plug assembly 142,144, 146 is located into recess 148, 150, 152 for sealing the connector32, 58, 96, respectively. Aluminum insert 160, 162, 164 is threaded ontothreaded portion 48.1, 74.1, 12.1 for securing the plug assembly 142,144, 146 onto connector 32, 58, 96, respectively. As presentlypreferred, the plug assembly 142, 144, 144 is tightened to a torquerating of about 25 to 35 ft.-lbs.

The foregoing description of the embodiments has been provided forpurposes of illustration and description. It is not intended to beexhaustive or to limit the disclosure. Individual elements or featuresof a particular embodiment are generally not limited to that particularembodiment, but, where applicable, are interchangeable and can be usedin a selected embodiment, even if not specifically shown or described.The same may also be varied in many ways. Such variations are not to beregarded as a departure from the disclosure, and all such modificationsare intended to be included within the scope of the disclosure.

What is claimed is:
 1. A busbar assembly for interconnecting electricalequipment in a power distribution system comprising: a conductorincluding a conductive rod surrounded by an insulator sleeve, theconductive rod having first and second ends extending from the insulatorsleeve, each of the first and second ends having a ball member formedthereon; a first connector including a first insulator body having aninterface configured to attach to a first electrical equipment unit anda first clamp mechanism disposed in the first insulator body andconfigured to electrically couple with the first electrical equipmentunit, wherein the first end of the conductor is received in a firstpassage formed in the first insulator body such that the first ballmember engages and electrically couples with the first clamp mechanism;and a second connector including a second insulator body having aninterface configured to attach to a second electrical equipment unit anda second clamp mechanism disposed in the second insulator body andconfigured to electrically couple with the second electrical equipmentunit, wherein the second end of the conductor is received within asecond passage formed in the second insulator body such the second ballmember engages and electrically couples with the second clamp mechanism.2. The busbar assembly of claim 1 further comprising: a second conductorincluding a second conductive rod surrounded by an second insulatorsleeve, the second conductive rod having third and fourth ends extendingfrom the second insulator sleeve, each of the third and fourth endshaving a ball member formed thereon; a third connector including a thirdinsulator body having an interface configured to attach to a thirdelectrical equipment unit and a third clamp mechanism disposed in thethird insulator body and configured to electrically couple with thethird electrical equipment unit, wherein the third end of the conductoris received in a third passage formed in the third insulator body suchthat the third ball member engages and electrically couples with thethird clamp mechanism; and wherein the fourth end of the secondconductor is received within a fourth passage formed in the secondinsulator body such the fourth ball member engages and electricallycouples with the second clamp mechanism and the conductive rod.
 3. Thebusbar of claim 2 wherein the second clamp mechanism comprises a dualclamping mechanism having a first clamp on the second ball member and asecond clamp on the fourth ball member.
 4. The busbar assembly of claims1 wherein each of the clamp mechanisms comprises a first clamp element,a second clamp element and a fastener received in an recess passageformed in the insulator body, the fastener extending through the firstand second clamp elements to secure the clamp mechanism to the ballmembers of the conductive rod.
 5. The busbar assembly of claim 4 whereinthe fastener comprises a threaded head portion, a nut received on thethreaded head portion, a shank extending from the threaded head portionand passing through the first and second clamp elements, and a threadedbody portion configured to engage with the electrical equipment unit. 6.The busbar assembly of claim 5 further comprising a plug assemblycomprising an insulator portion disposed within the recess passage and athreaded insert engaging the threaded head portion the fastener, whereinthe plug assembly is configured to sealably engage the connector.
 7. Thebusbar assembly of claim 6 wherein the fastener further comprises abiasing element interposed between the nut and the first clamp element.8. The busbar assembly of claims I wherein each of the connectorscomprises a semi-conductive boot surrounding the clamp mechanism and theends of the conductor.
 9. The busbar assembly of claims 1 wherein theconductor rod comprise a body portion, a neck portion extending from thebody portion and a spherical end portion, the neck portion and thespherical end portion joining to form a contact surface and define theball member.
 10. The busbar assembly of claims 1 further comprising aconductive covering on the busbar assembly, the conductive coveringincluding a conductor portion on the conductor, and a connector portionon each of the connectors, wherein the conductor portion and theconnector portions are conductively coupled when the busbar assembly isassembled.
 11. A power distribution system comprising: a firstswitchgear unit having a first contact; a second switchgear unit havinga second contact; and a busbar assembly interconnecting the first andsecond switchgear units, the busbar assembly including: a conductorhaving a conductive rod surrounded by an insulator sleeve, theconductive rod having first and second ends extending from the insulatorsleeve, each of the first and second ends having a ball member formedthereon; a first connector including a first insulator body having anfirst interface attached to the first switchgear unit and a first clampmechanism disposed in the first insulator body and configured toelectrically couple with the first contact of the first switchgear unit,wherein the first end of the conductor is received in a first passageformed in the first insulator body such that the first ball memberengages and electrically couples with the first clamp mechanism; and asecond connector including a second insulator body having an interfaceattached to the second switchgear unit and a second clamp mechanismdisposed in the second insulator body and configured to electricallycouple with the second contact of the second switchgear unit, whereinthe second end of the conductor is received within a second passageformed in the second insulator body such the second ball member engagesand electrically couples with the second clamp mechanism.
 12. The powerdistribution system of claim 11 further comprising: a third switchgearunit having a third contact; and the busbar assembly further including:a second conductor including a second conductive rod surrounded by ansecond insulator sleeve, the second conductive rod having third andfourth ends extending from the second insulator sleeve, each of thethird and fourth ends having a ball member formed thereon; a thirdconnector including a third insulator body having an interface attach tothe third switchgear unit and a third clamp mechanism disposed in thethird insulator body and electrically coupled with the third contact ofthe third switchgear unit, wherein the third end of the conductor isreceived in a third passage formed in the third insulator body such thatthe third ball member engages and electrically couples with the thirdclamp mechanism; and wherein the fourth end of the second conductor isreceived within a fourth passage formed in the second insulator bodysuch the fourth ball member engages and electrically couples with thesecond clamp mechanism and the conductive rod.
 13. The powerdistribution system of claim 12 wherein the second clamp mechanism ofthe busbar assembly comprises a dual clamping mechanism having a firstclamp on the second ball member and a second clamp on the fourth ballmember.
 14. The power distribution system of claims 11 wherein the clampmechanisms of the busbar assembly comprise a first clamp element, asecond clamp element and a fastener received in an recess passage formedin the first and second insulator bodies, the fastener extending throughthe first and second clamp elements to secure the clamp mechanisms tothe ball members of the conductor rod.
 15. The power distribution systemof claim 14 wherein the fastener comprises a threaded head portion, anut engaging the threaded head portion, a shank extending from thethreaded head portion and passing through the first and second clampelements, and a threaded body portion configured to engage with thecontact on the switchgear unit.
 16. The power distribution system ofclaim 15 wherein further comprising a plug assembly comprising aninsulator portion disposed within the recess passage and a threadedinsert engaging the threaded head portion of the fastener, wherein theplug assembly is configured to sealably engage the connector.
 17. Thepower distribution system of claim 16 wherein the fastener furthercomprises a biasing element interposed between the nut and the firstclamp element.
 18. The power distribution system of claims 11 whereineach of the connectors in the busbar assembly comprises asemi-conductive boot surrounding the clamp mechanism and the ends of theconductor.
 19. The power distribution system of claims II wherein eachof the conductor rods in the busbar assembly comprise a body portion, aneck portion extending from the body portion and a spherical endportion, the neck portion and the spherical end portion joining to forma contact surface and define the ball member.
 20. The power distributionsystem of claims 11 further comprising a conductive covering on thebusbar assembly, the conductive covering including a conductor portionon the conductor, and a conductor portion on each of the connectors inthe busbar assembly, wherein the conductor portion and the connectorportions are conductively coupled when the busbar assembly is assembled.